It sounds a little tight to me, but I guess the gun's performance will tell for sure. It would be interesting to slug it in segments, and get a idea of how it constricts, i.e.- whether it tapers down halfway, or just at the muzzle? Maybe it tapers gradually all the way? If it tapers gradually, and continuously down the bore, I don't think it would be all that bad, but if it constricts near the muzzle, it might cause a pressure jump that would give concern.